Adjustable-intensity electromagnetic audible-signal device



May 25, A B, PQQLE 2,442,016

ADJUSTABLE-INTENSITY ELECTROMAGNETIC AUDIBLE-SIGNAL DEVICE Filed Sept. 27, 1945 2 Sheets-Sheei: 1

- //v1//vr0 ARTHUR B. Foo

Patented May 25, 1948 ADJUSTABLE-INTENSITY ELECTED NETIC AUDlBLE-SIGNAL DEVICE MAG- Arthur B. Poole, Hamilton, Conn. Application September 27, 1945, Serial No. 618,865

10 Claims.

The present invention relates to improvements in electromagnetic audible-signal devices and relates more particularly to electromagnetic audible-signal devices having means for adjusting the intensity of the signal.

One of the objects of the present invention is to provide a superior audible-signal device of the character referred to, and having a simple construction and arrangement of parts combining low cost for manufacture with reliability of operation.

Another object of the present invention is to provide a superior electromagnetic audible-signal device comprising an electromagnet and an armature, and having a superior construction and arrangement of parts whereby the effective magnetic flux from the electromagnet and acting on the said armature may be conveniently varied without requiring the adjustment of the energy supplied to the said electromagnet.

A further object of the present invention is to provide a superior audible-signal device of the character referred to and comprising a cooperating electromagnet and an armature and having a simple and reliable construction and arrangement of parts whereby the magnetic flux developed by the said electromagnet may be efllciently employed in actuating the said armature gently or violently as may be desired.

With the above and other objects in view, as will appear to those skilled in the art from the present disclosure, this invention includes all features in the said disclosure which are novel over the prior art and which are not claimed in any separate application.

In the accompanying drawings, in which certain modes of carrying ut the present invention are shown for illustrative purposes:

Fig. 1 is a broken view in front elevation of one form of audible-signal device constructed in accordance with the present invention;

Fig. 2 is a rear view thereof;

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 1 but on a larger scale Fig. 4 is a perspective view of the electromagnet-unit, detached;

Fig. 5 is a similar view of the shell of the electromagnet;

Fig. 6 is a perspective view of the core-unit of the electromagnet;

Fig. 7 is a broken face-view of the mountingplate;

Fig. 8 is a broken sectional view similar to Fig. 3 but showing another form which the present invention may assume; and

Fig. 9 is a view similar to Fig. 8 but showing still another form which the present invention may assume.

The structure of Figs. 1 to 7 inclusive An embodiment of the present invention illustrated in the figures referred to. includes an electromagnet comprising a cup-shaped shell lo, a core II, a spool l2 and an energizing-coil l3.

The shell l0 and core ll above referred to are formed of soft iron or other suitable magnetic material while the spool i2 is preferably formed of insulating material and upon which the energizing-coil I3 is wound. The spool l2 and its energizing-coil I! are located within the cupshaped shell lfl while the core ll extends axially through the said shell, the spool l2 and the energizing-coil, as is especially well shown in Fig. 3.

The structure of Figs. 1 to 7, inclusive, also includes a mounting-plate l4 preferably formed of non-magnetic but electro-conductive material, an armature IS, an armature-arm IE to the intermediate portion of which the said armature I5 is rigidly attached, a stud I! by which the armature-arm I6 is secured at one of its ends to the mounting-plate l4, and a plate-like fluxshunting member l8. The structure also includes a concavo-convex spring-washer l9 and a retaining screw 20.

The shell Ill before referred to includes a substantially-cylindrical lateral wall 2| and an end wall 22 formed intergral with the rear end of the said lateral wall and centrally pierced for the accommodation of the rear portion of the core I I in such manner as to permit the latter to turn, for purposes as will hereinafter appear.

The lateral wall 2| of the shell ID of the electromagnet is preferably provided with two longitudinal slots 23-23 affording means where any suitable leads from the energizing-coil is may emerge for connection to a suitable source of electrical energy.

At its forward end the lateral wall 2| of the shell I0 is provided with two forwardly-projecting pole-salients 24 and 25 located diametrically opposite each other and respectively adapted to project forwardly through arcuate slots 26- and 21 extending from front to rear through the mounting-plate H as is especially well shown in Fig. 7. The pole-salients 24 and 25 are of sufficient length to project well beyond the front face of the mounting-plate I4 into position to coact with the armature I 5 and the flux-shunting member It in a manner as will hereinafter appear.

Preferably. and as shown, the mounting-plate I4 is also provided with a slot 28 leading from the outer wall of the arcuate slot 21 to the adjacent edge of the mounting-plate so that the said mounting-plate does not provide an electric circuit around the pole-salient 25 as it does around ner a lag in the flux passing through the polesalient 24 will occur, while no such lag will occur in the pole-salient 23, thereby serving to provide a more uniform pull upon the armature II,

The flux-shunting member I3 is formed of soft iron or other suitable material and is riveted or otherwise secured to the core II adjacent the forward end thereof. The said member I8 is adapted to be turned edgewise by the said core into and out of registration with the pole-salients 24 and 25 for the purpose of shunting or shortcircuiting more or less of the magnetic-flux bebetween the two said pole-salients on the one hand and the core I I on the other hand.

The flux-shunting member I3 normally has its rear face frictionally-engaged with the forward face of the mounting-plate I4 within the area circumscribed by the inner periphery of the lateral-wall 2| of the shell III. and is held in such engagement by the tension of the spring-washer II. The spring-washer I9 has its outer edge resting upon the rear face of the end wall 22 of the shell I3 and has its inner portion seated against the under face of the head of the stud 20 which latter is tightly threaded into the rear end of the core II so as to effectively become a part thereof for normal operating purposes.

The forward portion of the core II extends through a circular clearance-opening 29 formed in the mounting-plate I4 intermediate the areaate notches 23 and 21 as is especially well shown in Figs. 3 and '1. v

In addition to serving to hold the flux-shunting member I3 in engagement with the forward face of the mounting-plate I4, the springwasher I3 and the stud 20 also serve to hold the respective forward faces of the shell I0, and the spool I2 against the rear face of the mountingplate I4. 7

3 The energizing-coil I3 may be supplied'with alternating current in any suitable manner such for instance as 60 cycle 110 volt current or the said energizing-coil may be supplied with interrupted direct current in any suitable manner such for instance as in the manner common in the art of bells and buzzers.

The energization of the energizing-coil I3 will cause the pole-salients 24 and 25 of the shell III to. assume one polarity at a given instant while the adjacent end of the core II assumes an opposite polarity. The magnetic-flux thus produced will attract the armature I against tension of the resilient armature-arm I6. and will cause the striker 30 to strike any suitable object such as a bell or gong. As soon as the current supplied to the energizing-coil I3 is interrupted or reversed the tension of the resilient armaturearm I! will move the armature I5 away from the pole-salients 24 and 25 and the front end of the core II preparatory to the said armature being again attracted.

Should the movement of the armature I5 be not sufficiently violent to meet requirements of audibility, the flux-shunting member I8 may be turned from the full-registering position in which it is shown in Figs. 3 and 4, into a position of partial-registry or completely out-of-registry with the pole-salients 24 and 25. This movement of the flux shunting member will progressively cause the shunting of less and less of the magnetic-flux and will permit more of the said flux to act directly on the armature I5 to thereby increase the violence of the movement of the 4 said armature and hence greater audibllity of the signal produced.

If desired the striker 30 or its equivalent may be omitted to produce a buzzer-like effect occasioned by the vibration of the armature I5.

The structure ofFio. 8

The structure of Fig. 8 includes the shell Ill, spool l2, energizing-coil I3, mounting-plate I4, armature I5, armature-arm I3, stud I1 and striker 30 corresponding to the similar features in the structure of the preceding figures.

In lieu of the movable core II, the structure of Fig. 8 is provided with a stationary core 3i having an axial-passage 32 extending therethrough. Extending axially through the passage 32 in the core 3| is an adjusting-arbor 33 having rotary movement in the said passage.

Rigidly secured to the forward end of the adlusting-arbor 33, is a clamping-washer 34 serving to rigidly attach a flux-shunting member 35 similar to the flux-shunting member I8 previous ly described, to the said adjusting-arbor. The clamping-washer 34 as well as the member 35 is preferably formed of soft iron or other suitable .magnetic material so as to, in effect, constitute an extension of the forward end of the core 3|.

Rigidly mounted upon the projecting rear end of the adjusting-arbor 33, is a knurled fingerpiece 36 having its inner end seated against the central portion of a concavo-convex springwasher 31. The said spring-washer has its outer portion seated against the rear face of the end wall 22 of the shell I0 and has the adjustingarbor 33 extending through its central portion.

The core 3I is preferably rigid with the end wall 22 of the shell I0 and preferably as shown, its forward end is flush with the forward face of the mounting-plate i 4 when the device is assembled as shown in Fig. 8.

The tension of the spring-washer 31 not only serves to frictionally engage the rear face of the flux-shunting member 35 with the forward face of the mounting-plate I4, but also serves to hold the shell Ill and the parts carried thereby in assembled relationship with respect to the mounting-plate I4.

The device of Fig. 8 operates in substantially the same manner as the devices shown in Figs. 1 to 7 inclusive with the exception that the fluxshunting member 35 may be turned with respect to the pole-salients 24 and 25 by means of the adjusting-arbor 33 and the finger-piece 35, without requiring the rotation of the core 3|.

The structure of Fig. 9

The structure of Fig. 9 includes the parts and features previously designated by the reference characters I2, I3, I4, I6 to 20 inclusive and 25 to 30 inclusive together with a shell 38 similar to the shell Ill before referred to except that its forwardly-projecting pole-salients 39 and 40 are slightly longer than the pole-salients 24 and 25 of the said shell III. The shell 38 includes a lateral wall 4| having at its outer end an integral wall 42.

Mounted for rotation within the spool I2 and extending through the end wall 42 is a core 43 generally similar to the core II before described and like the same having the retaining-screw 2|i threaded into its rear end and passing through the spring-washer I9.

Rigidly secured to the forward portion of the core 43 is the flux-shunting member I8 before described in connection with the embodiment of the invention shown in Figs. 1 to '7 inclusive.

Forwardly oi the member II the core 43 is formed with a relatively slender neck 44 terminating in a disk-like head aperture 46 formed centrally in an armature 41.

The armature 41 is so sized as to freely ilt in the space between the pole-salients I9 and 40 and is secured in rearwardly spaced relationship to the armature-arm II by means of studs 4l40 When the energizing-coil It is supplied with current the armature 41 will be pulled inwardly until it substantially aligns with the head 45 of the core 43 to be again released to the tension of the resilient armature-arm it when the current supply is interrupted or reversed. The amount of flux which will be caused to flow through the armature 41 may be regulated by the position into which the flux-shunting member I! is turned in a manner similar to that described in connection with the preceding figures. The rotation of the core 43 will effect the desired turning movement of the flux-shunting member l8 as may be desired.

The particular arrangement of parts whereby the armature 4'! or its equivalent fits over the forward end of the core 43 and within the polesalients 39 and 40 is not per se claimed herein but forms the subject matter of a separate application filed on even date herewith and bearing Serial Number 618,866.

The invention may be carried out in other specific ways than those herein set forth without departing from the spirit and essential characteristics of the invention, and the present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.

I claim: I

1. An adjustable-intensity electromagnetic audible-signal device, including in combination: a movable signal-armature; an energizing-coil; two complemental magnetic members associated with the said energizing-coil and each having a portion of opposite instantaneous polarity as compared to the other and located adjacent the said signal-armature to pass magnetic flux there-' through; and adjustable flux-shunting means magnetically parallel with and providing a fluxpath independent of the flux-path provided by the said armature, the said-flux-shunting means being located adjacent the said signal-armature and the respective portions of the said magnetic members and constructed and arranged to adjustably divert magnetic flux between the said portions of the magnetic members and away from the said signal-armature to thus vary the violence of the movement of the latter.

2. An adjustable-intensity electromagnetic audible-signal device, including in combination: a movable signal-armature; an energizing-coil; two complemental magnetic members associated with the said energizing-coil with one thereof extending through the interior of the said energizingcoil and the other thereof extending over the exterior thereof, each of said magnetic members having a portion of opposite instantaneous polarity as compared to the other and located adjacent the said signal-armature to pass magnetic flux therethrough; and adjustable fluxshunting means magnetically parallel with and providing a flux-path independent of the fluxpath provided by the said armature, the said fluxshunting means being located adjacent the said signal-armature and the respective portions of 48 formally extending into an 6 the said magnetic members and constructed and arranged to adiustabiy divert magnetic flux between the said portions of the magnetic members and away from the said signal-armature to lthus vary the violence of the movement of the atter.

3. An adjustable-intensity electromagnetic audible-signal .device, including in combination: a movable signal-armature; an energizing-coil; a magnetic core extending through the interior of the said energizing-coil and having an end portion adjacent the said signal-armature; a magnetic member extending over the exterior of the said energizing-coil and provided with two polesalients located adjacent one end of the said core and adjacent the said signal-armature to cause the latter to carry flux between the two said polesalients and the said core; and adjustable fluxshunting means magnetically parallel with and providing a flux-path independent of the fluxpath provided by the said armature. the said flux-shunting means being located adjacent the said signal-armature, the pole-salients of the said member and the adjacent end of the said core and constructed and arranged to adjustably divert magnetic flux between the said pole-salients and the said core and away from the said signal-armature to thus vary the violence or the movement of the latter.

4. An adjustable-intensity electromagnetic audible-signal device, including in combination: a movable signal-armature; an energizing-coil; two complemental magnetic members associated with the said energizing-coil with one thereof extending through the interior of the said energizingcoil and the other thereof extending over the exterior thereof. each of said magnetic members having a portion of opposite instantaneous polarity as compared to the other and located adjacent the said signal-armature to pass magnetic flux therethrough; and an adjustable flux-shunting member mounted for turning movement about an axis substantially coaxial with the said energizlng-coil and magnetically parallel with and providing a flux-path independent of the fluxpath provided by the said armature, the said fluxshunting means being located adjacent the said signal-armature and the respective portions of the said magnetic members, the said flux-shunting member being constructed and arranged to adjustably divert magnetic flux between the said portions of the magnetic members and away from the said signal-armature to thus vary the violence of the movement of the latter.

5. An adjustable-intensity electromagnetic audible-signal device, including in combination: a movable signal-armature; an energizing-coil; a magnetic core extending through the interior of the said energizing-coil and having an end portion adjacent the said signal-armature; a magnetic member extending over the exterior of the said energizing-coil and provided with two polesalients located adjacent one end of the said core and adjacent the said signal-armature to cause the latter to carry flux between the two said polesalients and the said core; and an adjustable fluxshunting member magnetically parallel with and providing a flux-path independent of the fluxpath provided by the said armature, the said fluxshunting means being mounted for turning movement about an axis substantially coaxial with the said energizing-coil and the said core and located adjacent the said signal-armature, the polesalients of the said member and the adjacent end portion or the said core. the said flux-shunting 7 member being constructed and arranged to adjustably divert magnetic flux between the said pole-salients and the said core and away from the said signal-armature to thus vary the violence of the movement of the latter.

6. An adjustable-intensity electromagnetic audible-signal device, including in combination: a movable signal-armature; an energizing-coil; a rotatable magnetic core extending through the interior of the said energizing-coil and having an end portion adjacent the said signal-armature; a magnetic member extending over the exterior of the said energizing-coil and having a portion located adjacent the said signal-armature to cause the latter to carry flux between itself and the said core; an adjustable flux-shunting member located adjacent the said signal-armature and the respective portions of the said core and magnetic member to adjustably divert magnetic flux between the said magnetic member and the said core and away from the said signal-armature, the said flux-shunting member being secured to the end portion of the said core adjacent the said signal-armature for turning movement with the said rotatable core.

7 An adjustable-intensity electromagnetic audible-signal device, including in combination: a movable signal-armature; an energizing-coil; a rotatable magnetic core extending through the interior of the said energizing-coil and having an end portion adjacent the said signal-armature; a magnetic member extending over the exterior of the said energizing-coil and provided with two pole-salients located adjacent one end of the said core and adjacent the said si nal-armature to cause the latter to carry flux between the two said pole-salients and the said core; and an adjustable flux-shunting member located adjacent the said signal-armature, the pole-salients of the said member and the adjacent end of the said core and constructed and arranged to adjustably divert magnetic flux between the said pole-salients and the said core and away from the said signal-armature, the said flux-shuntin member being carried by and turnable with the said rotatable core.

8. An adjustable-intensity electromagnetic audible-signal device, including in combination: a movable signal-armature; an energizing-coil; two complemental magnetic members associated with the said energizing-coil with one thereof extending through the interior of the said energizingcoil and the other thereof extending over the exterior thereof, each of said magnetic members having a portion of opposite instantaneous polarity as compared to the other and located adjacent the said signal-armature to pass magnetic flux therethrough; an adjustable flux-shunting member magnetically parallel with and providing a flux-path independent of the flux-path provided by the said armature, the said flux-shunting means being located adjacent the said signalarmature and the respective portions of the said magnetic members and constructed and arranged to adjustably divert magnetic flux between the said portions of the magnetic members and away from the said signal-armature; and rotary adjusting-means also extending through the interior of the said energizing-coil and coupled to the said flux-shunting member to adjust same.

9. An adjustable-intensity electromagnetic audible-signal device, including in combination: a mounting-plate provided with a clearance-opening and with two salient-receiving openings respectively on either side of the said clearanceopening; a magnetic shell located to the rear of the said mounting-plate and provided with two pole-salients respectively projecting forwardly through the salient-receiving openings in the said mounting-plate; an energizing-coil within the i said magnetic shell; -a magnetic core extending through the interior of the said energizing-coil and having an end projecting forwardly through the clearance-opening in the said mountingplate; a movable signal-armature located forwardly of the said mounting-plate and cooperating with the pole-salients and the said shell and the adjacent end of the said core; an adjustable flux-shunting member mounted for turning movement about an axis substantially parallel with the axis of the said energizing-coil and located forwardly of the said mounting-plate and rearwardly of the said signal-armature, the said member being magnetically associated with the polesalients of the said shell and with the adjacent portion of the said core to shunt magnetic flux therebetween; nd means for turning the said flux-shunting member.

10. An adjustable-intensity electromagnetic audible-signal device, including in combination: a mounting-plate provided with a clearanceopening and with two salient-receiving openings respectively on either side of the said clearanceopening, the said mounting-plate also being formed with a passage leading from one of the said salient-receiving openings to an edge of the mounting-plate to avoid the circulation of eddycurrents in the portion of the mounting-plate around the particular one of the hereinaftermentioned pole-salients which extends through the salient-receiving opening from which the said passage leads; a magnetic shell located to the rear of the said mounting-plate and provided with two pole-salients respectively projecting forwardly through the salient-receiving openings in the said mounting-plate; an energizing-coil within the said magnetic shell; a magnetic core extending through the interior of the said energizingcoil and having an end projecting forwardly through the clearance-opening in the said mounting-plate; a movable signal-armature located forwardly of the said mounting-plate and cooperating with the pole-salients and the said shell and the adjacent end of the said core; an adjustable flux-shunting member mounted for turning movement about an axis substantially parallel with the axis of the said energizing-coil and located forwardly of the said mounting-plate and rearwardly of the said signal-armature, the said member being magnetically associated with the pole-salients of the said shell and with the adjacent portion of the said core to shunt magnetic flux therebetween; and means for turning the said flux-shunting member.

ARTHUR B. POOLE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,206,988 Clemens Dec. 5, 1916 1,906,027 Wahl Apr. 25, 1933 1,959,470 Haasis May 22, 1934 2,165,123 Ballantine July 4, 1939 2,318,359 Bellows, Jr. May 4, 1943 

